Representativeness isampula

Vyborka- le set of data ezithathwe iinkqubo ezifanelekileyo labantu ukwenzela uhlalutyo uphando. Representativeness - lo mhlaba ukudlalwa ntetho yonke amalungu ayo. Phezu komnye, kube lithuba ukusasazwa ingcamango lonke, ukuba le uhlanganisa.

Representativeness isampula - umlinganiselo, enala kwinto yokuba isampuli kufuneka zibonise zizo zonke iimpawu ngokupheleleyo kwaye ngokuthembekileyo, ezo ke inxenye. Kananjalo singachazwa njengento impahla isampuli amele kakhulu ngokupheleleyo iimpawu labemi, olubalulekileyo ukusuka kwindawo ngembono lweenjongo zophando.

Ukucinga ukuba abantu ngokubanzi - yonke abafundi yesikolo (900 abantu abasuka kwiiklasi-30, abafundi-30 kwiklasi nganye). Injongo yokufunda - umlinganiselo abafundi ukutshaya. Le sethi isampuli equka Abafundi 90 kuphela kwisikolo samabanga aphakamileyo, singasathethi lakalokunje, kukho ngokupheleleyo ngaphezu isampuli yabafundi 90 efanayo, nekukho Umfundi ngamnye eklasini 3. Isizathu - yokwaba zawo amaphakade. Ngenxa yoko, kwimeko yokuqala representativeness isampula kuya kuba phantsi. Kwimeko yesibini - phezulu.

Xa kwabantu, wathi ukuba kukho representativeness ye isampula representativeness yayo.

Ngokomzekelo, isampuli lula kungabangela kwityala zakudala, owenzeka ngo-1936 eUnited States ngexesha yokhetho.

Magazine "Literari Digest", apho oku kwangaphambili ngempumelelo kakhulu iziphumo zonyulo ezidlulileyo, eli xesha wenze impazamo kuqikelelo zabo, nangona wathumela imibuzo ebhaliweyo lwababhalisi million eziliqela, kwakunye abaphenduli abakhethwe kwincwadi yefowuni kwaye ukusuka kuluhlu zobhaliso lwesithuthi. Kulo lokuvota lesine, zabuya zizaliswe umva, yokuvota ngolu hlobo lulandelayo: 57% ukukhokelwa ngumviwa Republican Alf Landon wambiza, kwaye i-41% yabonisa kuthanda ngumongameli okweso - Democrat Franklin Roosevelt.

Enyanisweni, unyulo iphumelele Roosevelt, ngubani amanqaku phantse-60% ye-kuvotwe. Imposiso "Literari Digest" waba elandelayo. Babefuna ukwandisa representativeness isampula. Yaye ekubeni babesazi ukuba uninzi kubathengi babo bazichaze Republican, bagqiba ukwandisa isampuli ngenxa sabaphenduli, ukhetho lwabo iincwadi yefowuni kunye nezintlu zobhaliso imoto. Kodwa ke musani ukuthathela ingqalelo izinto ezikhoyo yaye okunene Balisusa nabaxhasi ngakumbi le Republican, kuba ngexesha le Great Depression kuba iimoto kunye phones mali abakumgangatho ophakathi eliphezulu. Ngabo aba becala Republican, hayi Democrats.

Kukho iindidi ezahlukeneyo zokusampula: elula random, serial, ekuso, mechanical nezidibeneyo.

Simple isampuli ejikelezayo kukukhetha kwisethi yonke leeyunithi phantsi ukufunda nakanjanina ngaphandle nkqubo.

isampulu Mechanical kusetyenziswa xa abantu ngendlela umyalelo, umzekelo, kukho ulandelelwano ethile leeyunithi (iinombolo zobhaliso labasebenzi, izintlu lonyulo, amanani amanani abaphenduli emfonomfono zokuhlala kunye izindlu, njalo njalo).

A Ukukhetha eqhelekileyo kusetyenziswa xa iseti lonke zingahlulwa zibe ngamaqela ngokohlobo. Xa usebenzisa inani ezinjalo kuba, umzekelo, imfundo, ubudala, amaqela asekuhlaleni, kuphononongo lwamashishini - isebe okanye umbutho eyahlukileyo kunye nabanye.

Ukukhetha Uthotho kuluncedo xa iiyunithi ezidityanisiweyo kuthotho encinane okanye iqela. La manqaku ingaba ibhetshi kweemveliso ugqibile, iiklasi zesikolo, amaqela abasebenzi kunye namanye amaqela.

isampuli Ludityanisiwe kubandakanya ukusetyenziswa zonke iintlobo zangaphambili kwiisampuli nendibaniselwano ezahlukahlukeneyo.